<template>
  <div class="goods">
    <div class="menu-wrapper" ref="menuWrapper">
      <ul>
        <li v-for="(item,index) in goods" class="menu-item" :class="{'current':currentIndex === index}" @click="selectMenu(index,$event)">
          <span class="text border-1px">
           <span v-show="item.type > 0" class="icon" :class="classMap[item.type]"></span> {{item.name}}
          </span>
        </li>
      </ul>
    </div>
    <div class="foods-wrapper" ref="foodsWrapper">
      <ul>
        <li v-for="item in goods" class="food-list food-list-hook">
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li v-for="food in item.foods" class="food-item border-1px">
              <div class="icon">
                <img width="57" height="57" :src="food.icon">
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p v-show="food.description" class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}份</span><span>好评率{{food.rating}}%</span>
                </div>
                <div class="price">
                  <span class="now">￥{{food.price}}</span><span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cartcontrol @event="getEvent" :food="food"></cartcontrol>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <shopcart ref="shopcart"  :select-foods="selectFoods" :delivery-price="seller.deliveryPrice" :min-price="seller.minPrice"></shopcart>
  </div>
</template>

<script type="text/ecmascript-6">
  import BScroll from 'better-scroll'
  import shopcart from '@/components/shopcart/shopcart'
  import cartcontrol from '@/components/cartcontrol/cartcontrol'
  const ERR_OK = 0
    export default {
      props: {
        seller: {
          type: Object
        }
      },
      data () {
          return {
            goods: [],
            listHeight: [],
            scrollY: 0,
            selectedFood: {}
          }
        },
      props: {
          seller: {
            type: Object
          }
      },
      computed: { // vue的计算属性
          currentIndex() {
            for (let i = 0; i < this.listHeight.length; i++){
                let height1 = this.listHeight[i]
                let height2 = this.listHeight[i + 1]
              if(!height2 || (this.scrollY >= height1 && this.scrollY < height2)){
                 return i
              }
            }
            return 0
          },
        selectFoods() {
          let foods = []
          this.goods.forEach((good) => {
            good.foods.forEach((food) => {
              //如果food的count存在 不为0 放入foods集合里
              if(food.count) {
                foods.push(food)
              }
            })
          })
          return foods
        }
      },
      created() {
          this.classMap = ['decrease','discount','special','invoice','guarantee']

            this.$http.get('/api/goods').then((respons) => {
            respons = respons.body
            if(respons.errno === ERR_OK){
              this.goods = respons.data
              this.$nextTick(() => {
                this._initScrool() // 初始化dom 滚动
                this._calculateHeight() // 计算高度
              })
            }
          })
      },
      methods: {
        // 左右连动映射
        selectMenu (index,event) {
            // 知己派生的点击事件 有(_constructed属性: true)   浏览器默认的点击事件没有该属性  这样手机和PC 一样
            if(!event._constructed) {
              return
            }
            let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook')
            let el = foodList[index]
            this.foodsScroll.scrollToElement(el,300)
          },
        _initScrool() {
            // this.$refs：取得DOM对象
            this.menuScroll = new BScroll(this.$refs.menuWrapper, {
              click: true,//取消默认阻止事件   以至于在betterscroll组件里可以实现点击事件
              // probeType: 3
            })
            this.foodsScroll = new BScroll(this.$refs.foodsWrapper, {
              click: true, //取消默认阻止事件
              probeType: 3   //监听事件的触发时间，1为即时触发，3为延迟到事件完毕后触发
            })
             // 监听接口 scroll 实时拿到 y的高度
            this.foodsScroll.on('scroll', (pos) => {
              this.scrollY = Math.abs(Math.round(pos.y))
            })
          },
        _calculateHeight () {
          let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook')
          let height = 0
          this.listHeight.push(height)
          for (let i = 0; i < foodList.length; i++) {
            //获取每个li的高度，放入一个数组中
            let item = foodList[i]
            height += item.clientHeight
            this.listHeight.push(height)
          }
        },
        getEvent (el) {
          // 体验优化,异步执行下落动画    在goods组件点击小球 把他的dom传给购物车组件的drop()方法
          this.$nextTick(() => {
            this.$refs.shopcart.drop(el)
          })
        }
      },
      components: {
        shopcart,
        cartcontrol
      }
    }
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../common/stylus/mixin.styl"
  .goods
    display: flex
    position: absolute
    top: 174px
    bottom: 46px
    width: 100%
    overflow: hidden
    .menu-wrapper
      flex: 0 0 80px
      width: 80px
      background: #f3f5f7
      .menu-item
        display: table
        height 54px
        width: 56px
        line-height: 14px
        padding: 0 12px
        &.current
          position: relative
          z-index: 10
          margin-top: -1px
          background: #fff
          font-weight: 700
          .text
            border-none()
        .icon
          display: inline-block
          vertical-align: top
          width: 12px
          height: 12px
          margin-right: 2px
          background-size: 12px 12px
          background-repeat: no-repeat
          &.decrease
            bg-image('decrease_3')
          &.discount
            bg-image('discount_3')
          &.guarantee
            bg-image('guarantee_3')
          &.invoice
            bg-image('invoice_3')
          &.special
            bg-image('special_3')
        .text
          display: table-cell
          width: 56px
          vertical-align: middle
          border-1px(rgba(7,17,27,0.1))
          font-size: 12px
    .foods-wrapper
      flex: 1
      .title
        padding-left: 14px
        height: 26px
        line-height: 26px
        border-left: 2px solid #D3D4D6
        font-size: 12px
        color: rgb(147,153,159)
        background: #f3f5f7
      .food-item
        display: flex
        margin: 18px
        padding-bottom: 18px
        border-1px(rgba(7,17,27,0.1))
        &:last-child
          border-none()
          margin-bottom: 0
        .icon
          flex: 0 0 57px
          margin-right: 10px
        .content
          flex: 1
          .name
            margin: 2px 0 8px 0
            height: 14px
            line-height: 14px
            font-size: 14px
            color: rgb(7,17,27)
          .desc,.extra
            line-height: 10px
            font-size: 10px
            color: rgb(147,153,159)
          .desc
            line-height: 12px
            margin-bottom: 8px
          .extra
            .count
              margin-right: 12px
          .price
            font-weight: 700
            line-height: 24px
            .now
              margin-right: 8px
              font-size: 14px
              color: rgb(240,20,20)
            .old
              text-decoration: line-through
              font-size: 10px
              color: rgb(147,153,159)


          .cartcontrol-wrapper
            position: absolute
            right: 0
            bottom: 12px
</style>
